I'm playing a one-handed Khajiit who only uses maces, archery and very little destruction magic. He's a sellsword type- mercenary for hire if you will.

I'm getting ROCKED by ice wraiths, hagravens and the like.

Can you offer advice, help?

Well, my answer will look stupid I guess: avoid them until you have the proper level.

Well, are your weapons improved? Do you have any fortify weapon skill apparel? What's your 1H skill level and are you perked up?

I would say that by level 18 your main weapon skill should be about 60 and total damage with improvements and fortifications should be about 50-60 plus any enchantments.

Hargravens and Ice Wraiths are quite tough. Use better tactics. Fire is very effective against Ice Wraiths. Hargravens, just attack them from afar dodging the spells, or get up in their face to stagger them so that they can't cast. I try to sneak up and get the first shots in with my bow before they see me.

Note about the Ice Wraiths: Sometimes when battling them you can have their magic effect (the freezing plume behind them) applied to your character, usually your boots. If you notice this, just reload an earlier save, it's about the only way to fix this. Even the console commands can't get rid of this. It is a rare thing to happen, it never happened to me, so you may never need to do this.

I believe armor rating is the problem. That's why he keeps dying over and over.

Hey... maybe what you're wearing is too weak for lvl 18. And getting the perks that increase it is vital too.

Defense: You need fire-resistance for hagravens and cold-resistance for ice wraiths.

Offense: A mace with fire damage will do.

Hagravens and Ice Wraiths are hard creatures anyway. Ice Wraiths move fast and are hard to see, plus they use Frost magic which slows you down and drains Stamina. Hagravens use powerful Destruction spells and I think they're melee attack is pretty good too.

My advice: Just get a few more levels before you attempt them. Your weapons and armor might also need improving, depending on what they are.